Thin (4nm) epitaxial gold substrates prepared by vacuum evaporation under low energy electron bombardment are used as support films for DNA deposited from 0.1 m ammonium acetate solution. Continued epitaxial deposition of gold at 150 degrees C after prior deposition of DNA gives rise to an epitaxial sandwich in which the DNA is (at least partially) occluded between the gold layers. The DNA gives rise to diffraction contrast in transmission electron microscopy associated with displacement of the gold lattice in the neighborhood of the biopolymer. (Not mass-thickness contrast). It is now proposed to optimize the conditions for obtaining DNA sandwiches, especially with respect to the vacuum system. It is further proposed to establish conditions for preparing samples of DNA from sources other than T4 phage (e.g. gamma, DNA) and to examine in more detail the limits of contrast and resolution in specimens of biopolymer prepared by this technique.